sb optimized away the ELSE in a construct like
while (foo) {
if (bar ) {
do something;
} else {
break;
}
}
resulting in
while (foo) {
if (bar ) {
do something;
break;
}
}
which is obviously wrong.
With this patch an ELSE is inserted also if there was one before optimization.
This fixes piglit shaders@ssa@fs-if-def-else-break.
It might introduce a penalty by keeping an ELSE instruction when it can
actually be really optimized away though.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=101442
---
I think there should be a better way to ensure that the else is inserted
in this case, but so far it elluded me.
I have no mesa-git write access.
src/gallium/drivers/r600/sb/sb_bc_finalize.cpp | 4 +---
src/gallium/drivers/r600/sb/sb_bc_parser.cpp | 5 ++++-
src/gallium/drivers/r600/sb/sb_ir.h | 3 ++-
3 files changed, 7 insertions(+), 5 deletions(-)
diff --git a/src/gallium/drivers/r600/sb/sb_bc_finalize.cpp
b/src/gallium/drivers/r600/sb/sb_bc_finalize.cpp
index 099b295f18..4450247caf 100644
--- a/src/gallium/drivers/r600/sb/sb_bc_finalize.cpp
+++ b/src/gallium/drivers/r600/sb/sb_bc_finalize.cpp
@@ -208,9 +208,7 @@ void bc_finalizer::finalize_if(region_node* r) {
r->push_front(if_jump);
r->push_back(if_pop);
- bool has_else = n_if->next;
-
- if (has_else) {
+ if (n_if->has_else || n_if->next) {
cf_node *nelse = sh.create_cf(CF_OP_ELSE);
n_if->insert_after(nelse);
if_jump->jump(nelse);
diff --git a/src/gallium/drivers/r600/sb/sb_bc_parser.cpp
b/src/gallium/drivers/r600/sb/sb_bc_parser.cpp
index 970e4141d5..f37067b8e2 100644
--- a/src/gallium/drivers/r600/sb/sb_bc_parser.cpp
+++ b/src/gallium/drivers/r600/sb/sb_bc_parser.cpp
@@ -959,8 +959,11 @@ int bc_parser::prepare_if(cf_node* c) {
c->insert_before(reg);
- if (c_else != end)
+ if (c_else != end) {
+ n_if->has_else = true;
dep->move(c_else, end);
+ }
+
dep2->move(c, end);
reg->push_back(dep);
diff --git a/src/gallium/drivers/r600/sb/sb_ir.h
b/src/gallium/drivers/r600/sb/sb_ir.h
index bee947504e..af9b161597 100644
--- a/src/gallium/drivers/r600/sb/sb_ir.h
+++ b/src/gallium/drivers/r600/sb/sb_ir.h
@@ -1091,12 +1091,13 @@ public:
class if_node : public container_node {
protected:
- if_node() : container_node(NT_IF, NST_LIST), cond() {};
+ if_node() : container_node(NT_IF, NST_LIST), cond(), has_else(false) {};
public:
value *cond; // glued to pseudo output (dst[2]) of the PRED_SETxxx
virtual bool accept(vpass &p, bool enter);
+ bool has_else;
friend class shader;
};
--
2.13.6
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